Evaluating the effects of vanadyl sulfate on biomarkers of oxidative stress and inflammation in renal tissue of rats with diabetes type 2

Vanadyl sulfate (VS) is an ingredient in some food supplements and experimental drugs. This study was designed to assay the effects of VS on biomarkers of oxidative stress and inflammation in renal tissue of rats with diabetes type 2. 30 male Wistar rats were divided into three equal groups as follow: non-diabetics, non-treated diabetics and VS-treated diabetics. Diabetes type 2 has been induced through high fat diet and fructose in the animals. Diabetic rats were treated with 25 mg/kgBW of VS in water for 12 weeks. At the end of study, glucose and insulin were measured using commercially available kits in serum and biomarkers of oxidative stress and inflammation in renal homogenates of animals were measured by related methods. Compared to controls, glucose and insulin were increased significantly in non-treated diabetic rats (p-value <0.05) that showed the induction of diabetes type 2 in rats. The results showed that in VS-treated diabetic rats compared to the non-treated diabetic group, vanadyl sulfate significantly reduced the glucose and insulin secretion and changed renal inflammatory and oxidative markers, except protein carbonyl so that we couldn't find any significant changes. Our study showed that vanadyl supplementation had positive effects on oxidative stress and inflammation biomarkers in kidney of diabetic rats

Development of a novel resin with antimicrobial properties for dental application

The adhesion of biofilm on dental prostheses is a prerequisite for the occurrence of oral diseases. Objective: To assess the antimicrobial activity and the mechanical properties of an acrylic resin embedded with nanostructured silver vanadate (β-AgVO3). Material and Methods: The minimum inhibitory concentration (MIC) of β-AgVO3 was studied in relation to the species Staphylococcus aureus ATCC 25923, Streptococcus mutans ATCC 25175, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. The halo zone of inhibition method was performed in triplicate to determine the inhibitory effect of the modified self-curing acrylic resin Dencor Lay - Clássico®. The surface hardness and compressive strength were examined. The specimens were prepared according to the percentage of β-AgVO3 (0%-control, 0.5%, 1%, 2.5%, 5%, and 10%), with a sample size of 9x2 mm for surface hardness and antimicrobial activity tests, and 8x4 mm for the compression test. The values of the microbiologic analysis were compared and evaluated using the Kruskal-Wallis test (α=0.05); the mechanical analysis used the Shapiro-Wilk's tests, Levene's test, ANOVA (one-way), and Tukey's test (α=0.05). Results: The addition of 10% β-AgVO3 promoted antimicrobial activity against all strains. The antimicrobial effect was observed at a minimum concentration of 1% for P. aeruginosa, 2.5% for S. aureus, 5% for C. albicans, and 10% for S. mutans. Surface hardness and compressive strength increased significantly with the addition of 0.5% β-AgVO3 (p<0.05). Higher rates of the nanomaterial did not alter the mechanical properties of the resin in comparison with the control group (p>0.05). Conclusions: The incorporation of β-AgVO3 has the potential to promote antimicrobial activity in the acrylic resin. At reduced rates, it improves the mechanical properties, and, at higher rates, it does not promote changes in the control. .

Efeito do sulfato de vanadil sobre o comprometimento metabólico muscular induzido pela imobilização de membro posterior de ratos / Efecto del sulfato de vanadil sobre comprometimiento metabólico muscular inducido por la inmovilización del miembro posterior en ratones / Effect of the vanadyl sulphate on the muscular metabolic compromising induced by immobilization of posterior limb of rats

A proposta deste trabalho foi avaliar o efeito do sulfato de vanadil (SV) no perfil metabólico muscular de membro posterior imobilizado de ratos. Ratos Wistar foram divididos nos grupos (n = 6): controle (C), imobilizado em posição neutra do tornozelo (I), tratado com sulfato de vanadil (SV, 0,25mM, VO) e imobilizado tratado com SV (I + SV) durante sete dias. Após o período experimental, foram avaliadas as reservas de glicogênio (RG) dos músculos sóleo (S), gastrocnêmio branco (GB) e vermelho (GV), tibial anterior (TA) e extensor longo dos dedos (ELD), além do peso do S e ELD. A análise estatística foi realizada pela ANOVA seguida pelo teste de Tukey (p < 0,05). No grupo SV, os resultados mostraram elevação significativa nas RG (S 110 por cento, GB 71 por cento, GV 85 por cento, TA 125 por cento, EDL 108 por cento) e no peso (S 9 por cento, EDL 11 por cento). A imobilização reduziu significativamente as RG (S 31,6 por cento, GB 56,6 por cento, GV 39,1 por cento, ELD 41,7 por cento, TA 45,2 por cento) e peso (S 34,2 por cento e ELD 27 por cento); já no grupo I + SV, houve o aumento das RG em todos os músculos (S 211 por cento, GB 115 por cento, GV 148 por cento, ELD 161,9 por cento, TA 147 por cento), além de impedir a perda de peso do S (75 por cento) e ELD (46 por cento). O tratamento com sulfato de vanadil promoveu elevação nas reservas de glicogênio do grupo controle e imobilizado, além de impedir a perda de peso, demonstrando que seu efeito insulino-mimético é representado pela ação glicogênica associado a uma possível ação anticatabólica.

The purpose of this study was to evaluate the metabolic performance of immobilized skeletal muscle in rats treated with vanadyl sulphate. Male Wistar rats were divided in groups (n = 6): control (C), immobilized (I), treated with vanadyl sulphate (VS, 0,25 mM) and immobilized treated with vanadyl sulphate (I + VS) during seven days. The concentration of vanadyl sulphate diluted in water was 0,25 mM. After experimental stage, the glycogen content (GC) was evaluated in soleus (S), white gastrocnemius (WG), red gastrocnemius (RG), tibialis anterior (TA) and extensor digitorum longus (EDL) muscles, besides S and EDL weight. The statistical analysis was realized by the ANOVA followed by Tukey test (p < 0,05). In VS group, the results showed a significant increase in GC (S 110 percent, WG 71 percent, RG 85 percent, TA 125 percent, EDL 108 percent) and in the weight (S 9 percent, EDL 11 percent). The immobilization reduced significantly the GC (S 31.6 percent, WG 56.6 percent, RG 39.1 percent, EDL 41.7 percent, TA 45.2 percent) and weight (S 34.2 percent and ELD 27 percent), and in I + VS group, there was a increase of the GC in all muscles (S 211 percent, WG 115 percent, RG 148 percent, EDL 161.9 percent, TA 147 percent), besides hindering the weight loss in S (75 percent) and EDL (46 percent). The vanadyl sulphate treatment promoted an increase in the glycogen content of control and immobilized groups, besides hindering the weight loss, showing that the insulino-mimetic effect is represented by glycogenic action associate to a possible anti-catabolic action.

La propuesta de este trabajo ha sido la de evaluar el efecto del sulfato de vanadil (SV) en el perfil metabólico muscular de miembro posterior inmovilizado de ratones. Ratones Wistar fueron divididos en grupos (n = 6): control (C), inmovilizado en posición neutra de tobillo (I), tratado con sulfato de vanadil (SV, 0,25mM, VO) e inmovilizado tratado con SV (I + SV) durante 7 días. Después del periodo experimental, fueron evaluadas las reservas de glicógeno (RG) de los músculos soleo (S), gastrocnemio blanco (GB) y colorado (GV), tibial anterior (TA) y extensor largo de los dedos (ELD), además del peso de S y ELD. El análisis estadístico fue realizado por ANOVA seguido del test de Tukey (p < 0,05). En el grupo SV, los resultados mostraron elevación significativa en las RG (S 110 por ciento, GB 71 por ciento, GV 85 por ciento, TA 125 por ciento, EDL 108 por ciento) y en el peso (S 9 por ciento, EDL 11 por ciento). La inmovilización redujo significativamente las RG (S 31,6 por ciento, GB 56,6 por ciento, GV 39,1 por ciento, ELD 41,7 por ciento, TA 45,2 por ciento) y peso (S 34,2 por ciento e ELD 27 por ciento), por otro lado en el grupo I + SV, hubo aumento de las RG en todos los músculos (S 211 por ciento, GB 115 por ciento, GV 148 por ciento, ELD 161,9 por ciento, TA 147 por ciento), además de impedir la pérdida de peso de S (75 por ciento) y ELD (46 por ciento). El tratamiento con sulfato de vanadil promovió una elevación en las reservas de glicógeno del grupo control e inmovilizado, además de impedir la pérdida de peso, lo que demuestra que su efecto insulina mimético está representado por la acción glicogénica asociado a una posible acción anticatabólica.

Evaluation of photodynamic activity of octaethylporphyrin and vanadyl octaethylporphyrin

Objective: in this work we have investigated the photodynamic efficiency of octaethylporphyrin (OEP) and vanadyl octaethylporphyrin(VOOEP). Methods: this study was performed by the evaluation of photophysical parameters of these porphyrins, the photooxidationrate constants (kf) of the biomolecules (tryptophan -Trp and bovine serum albumin - BSA) and the erythrocytes photodestructionpercentage. Results: photophysical parameters value such as singlet oxygen quantum yield (Õ∆) and triplet state lifetime (ôT)indicated that OEP (Õ∆= 0.64 ±0.02, tT= 0.91 ± 0.02 ms) is more efficient than VOOEP (Õ∆= 0.26 ±0.02, tT= 0.22 ± 0.03ms). The values of kf/10-4 s-1for Trp and BSA photoxidation demonstrated that OEP (Trp= 2.80 ± 0.05 and BSA= 2.50 ± 0.1)is more efficient than VOOEP (Trp= 0.81 ± 0.08 and BSA= 0.62 ± 0.04). The photodestruction percentage of erythrocytesrevealed that the photodynamic activity of OEP is more pronounced than photoactivity of VOOEP. These results indicated thatdifferences observed in the photodynamic activity between the porphyrins could be associated with differences in their molecularstructures. Conclusion: photophysical parameters, photooxidation of biomolecules, and photodestruction of erythrocytes clearlyindicate that the vanadyl group (V=O) interferes in the photoactivity of OEP, causing a considerable reduction in its efficiency.

Kinetic studies on the membrane form of intestinal alkaline phosphatase

We have purified different membrane and soluble forms of alkaline phosphatase from human placenta and bovine intestine. The enzymes will be used as markers in immunoconjugates and/or as model for membrane enzyme studies. The membrane formof alkaline phosphatase extracted from bovine intestine was purified on Q-Sepharose and on L-histidyldiazobenzylphosphonic acid-agarose columns to remove phosphodiesterase activity. The purified enzyme had a molecular mass of 61 kDa, Km of 1208 µM, and Vmax 240 µmol pNP/min when assayed in 1 M diethanolamine, 0.5 mM MgCl2 buffer, pH 9.8, containing 10 to 2250 µM of pNPP at 37§C. In the present investigation we studied the effect of salts and inositol derivatives on this enzyme activity, which was found to depend on 0.5 mM Mg2+, and to be fully inhibited by 1.2 mM Hg2+. Vanadate (0.5 mM) and Zn2+ (0.5 mM) reduced the Km value by 43 percent and 84 percent, respectively. Inositol (2 mM) and inositol-2-monophosphate (2 mM) reduced the activity by 23 percent and 17 percent. Inositol-1-monophosphate (0.5 mM) and cyclic-inositol-(1:2)-monophosphate (0.5 mM) enhanced their Km value by at least 30 percent compared to p-nitrophenylphosphate

Calcium homeostasis in Trypanosoma cruzi

By using the fluorescent Ca2+ indicator fura 2, submicromolar levels of intracellular Ca2+ have been detected in Trypanosoma cruzi different stages. The intracellular transport mechanisms involved in maintaining Ca2+ homeostasis in T. cruzi have been characterized by measuring Ca2+ transport in digitonin-permeabilized cells. Two intracellular calcium transport systems have been detected. Ca2+ uptake by the mitochondria occurs by an electrophoretic mechanism, is inhibited by antimycin A, FCCP, and ruthenium red, and stimulated by respiratory substrates, phosphate and acetate. This pool has a high capacity and low affinity for Ca2+ and is able to buffer external Ca2+ at concentrations in the range of 0.6-0.7 microM. Ca2+ uptake by the endoplasmic reticulum is inhibited by high concentrations of vanadate and anticalmodulin agents, and stimulated by ATP. This pool has a low capacity and a high affinity for Ca2+ and is able to buffer external Ca2+ at concentrations in the range of 0.05-1.0 microM. In addition, calmodulin has been purified from T. cruzi epimastigotes and shown to stimulate the homologous plasma membrane Ca(2+)-ATPase and cyclic-AMP phosphodiesterase. The gene encoding this protein has been cloned and sequenced and shown to have a great homology to mammalian calmodulin. The role of the plasma membrane of T. cruzi in the regulation of [Ca2+]i has been studied using fura 2-loaded epimastigotes or plasma membrane vesicles prepared from epimastigotes. Plasma membrane vesicles transport Ca2+ in the presence of Mg2+ and have a high affinity, vanadate-sensitive (Ca(2+)-Mg2+)-ATPase with an apparent Km for free Ca2+ of 0.3 microM.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparasion between plasma membrane Ca2 + and Na, K-ATPases: short review

This paper is a short review of the comparative biochemistry of the Na, K-ATPase and Ca2+ -ATPase of plasma membranes. The two ATPases share the same biphasic activation by ATP. Ca2+ - ATPase activation by ATP is strongly affected by calmodulin. The possibility of Mg2+ occlusion is proposed in connection with low-affinity activation by ATP. Both ATPase are activated by alkaline earth metal ions and display phosphatase activity toward p-nitrophenylphosphat for which Ca2 + - ATPase is strongly dependent on K + and regulated by calmodulin. The requirements for ligands of the phosphatase activity of both ATPase are strikingly similar except for the effect of calmodulin. Both ATPases are inhibited by vanadat and for both the effect of vanadate is modulated by Mg2+ and K + in the same way. These similarities indicate that, although Ca2 + - ATPase and Na, K-ATPase are different enzymes, their mechanisms of action may have more feactures in common than previously thought